1. Field of the Invention
The present invention relates to a signal processing method and a signal processing device for a frequency-modulated continuous waveform (FMCW) radar system, and more particularly, to a signal processing method and a signal processing device capable of enhancing tracing stability of the FMCW radar system and reducing missing rate of the FMCW radar system.
2. Description of the Prior Art
According to the statistics, most of traffic accidents are related to drivers' distraction. If a driver is alerted at 0.5 seconds before being likely to have a collision, it can avoid at least 60% of rear-end collisions, 30% of head-on collisions and 50% of road ramp related traffic accidents. If alerted before one second, it can avoid 90% of traffic accidents. The statistics shows traffic accidents can be effectively reduced if the drives have enough reaction time. Vehicle alarm systems, e.g., a blind spot detection (BSD) system, a forward/rear collision warning system, are smart vehicle equipment developed for such needs.
Common vehicle alarm systems utilize frequency-modulated continuous waveform (FMCW) radar technique to achieve early warning. More specifically, the vehicle alarm system uses an image self-recognition method of machine vision to detect obstacles in specific areas on left/right/front sides of a vehicle, so as to send out an alarm before collision happens. Nevertheless, under a situation that there are two targets within a sensing area of the FMCW radar system, if a velocity difference or a distance difference of these two targets is so small that these two targets may not be distinguished, a miss of the vehicle alarm system may happen, i.e., the vehicle alarm system fails to send out an alarm when the vehicle alarm system should alarm, which may indirectly cause traffic accidents.
In such a situation, how to enhance an accuracy of the FMCW system and reduce a missing rate of the FMCW system, so as to enhance traffic safety, is a significant objective in the field.